小笠原西之島火山の活動とその経過
1974 年 83 巻 2 号 p. 125-133
詳細
1974 年 83 巻 2 号 p. 125-133
A submarine volcano near Nishinoshima, Bonin Islands, began its activity in about April 1973. At first only the colored zone on the sea by the eruption was found. In. May the smoke and the small eruptions were recognized. In June the reef sometimes appeared. In September there appeared a new volcanic island. It grew up to the island, which was about 600 m long from east to west, about 300 m from north to south and about 60 m high as of 21 December. During these times the, pit moved on 700 m. According to the results of the investigations on 31 May, 5 July, 14 September, 9 October and 21 December and the informations collected the author reports the development of the volcano.
